Mercedes-Benz upgraded its SLS flagship Coupe and Roadster for the 2013 model year, and the changes are marked with them new "GT" nomenclature. Both SLS models arrive with a retuned naturally aspired 6.2-liter V8 delivering 583 horsepower and 479 pound-feet of torque (the horses are up from 563, but the torque remains the same) mated to a revised seven-speed AMG Speedshift dual-clutch gearbox. Rounding out the mechanical upgrades is a redeveloped AMG two-mode adaptive suspension. Physically, the revised models are differentiated by their new "GT" badging, darkened headlight/taillight buckets, red brake calipers, unique wheel colors and high gloss finish on the front grille, exterior mirrors and hood/fender fins. Inside the cabin are new red seatbelts, Alcantara upholstery and contrasting red stitching.
As it is nearly impossible to experience the aluminum gullwing beast on public roads, Mercedes invited out to Southern California's Willow Springs to wring out the 2013 SLS GT Coupe on a racing circuit.
- It was impossible to feel the horsepower bump from the driver's seat (the track's 2,000-foot elevation negated the increase anyway), but the free-breathing V8 sounds even more spectacular each time I meet it. Gobs of low-end torque, a responsive throttle and a willingness to race to redline (7,200 rpm) make it a near-perfect driver's companion. The automaker quotes a 0-60 time of 3.7 seconds – traction at launch is a problem – with a top speed of 197 miles per hour. The SLS attacked the Streets of Willow with voraciousness. I've driven hundreds of laps on the circuit, but never in a vehicle so powerful that I needed to brake hard to make Turn One after rocketing down the straight (running clockwise).
- After finding myself bumping off the limiter repeatedly while using the wheel-mounted paddles in manual mode (an LED shift light blinks red at the top of the cluster), I put the gearbox in Sport Plus and let computers do the thinking. Overall, I was pleased with its intuitiveness and I really enjoyed the throttle blips on the downshifts.
- A near complete lack of body roll and very firm AMG Sport suspension (I chose the damper's softest setting to combat the surface's broken pavement) meant the rear end would break loose mid-corner if the power was applied abruptly. Smoothness and consistent throttle applications were imperative to keeping the rear end planted and exiting the corner with the nose pointed down the track. Overall balance was impressively neutral and weight distribution, fore and aft, was easily controlled with the accelerator pedal.
- The 15.4-inch perforated front steel rotors could take plenty of abuse, but I preferred the optional carbon-ceramic brake setup as they felt unaffected by the heat generated on the tight track. As an added benefit, they weigh less and look even better through the forged spokes on the wheels.
- Driven back-to-back on the track, the updated Coupe and Roadster were nearly identical dynamically (they both weigh 3,573 pounds). From a driver's perspective, the exhaust note is more pronounced in the Roadster and there was more wiggle room for my helmeted head beneath its soft convertible top. Still, I wouldn't want to give up those signature gullwing doors.